Deep well pump



Nov. 3, 1936. R. L CHENAULT DEEP WELL PUMP Filed NOV. 19, 1935 PatentedNov. 3, 1936y DEEP WELL PUMP Roy L. Chenault, Pittsburgh, Pa., assignerto Guit Research & Development Company, Pittsburgh, Pa., a corporationof Delaware Application November 19, 1935,-Serlal No. 50,580 s claims.(cl. 10a- 234),

l This invention relates to deep well pumps, and it comprises a pumphaving a displacement chamber submerged in the liquid of a well and fromwhich chamber the liquid is forced by pneumatic,

pressure to the surface of the well through a reciprocable eduction pipewhich includes valve means at its lower end for alternately admitting a.limited amount of liquid to the displacement chamber and thenestablishing communication with a source of pneumatic pressure forexpelling the liquid therefrom into the eduction pipe, the valve meanshaving a sealing partition to prevent rise of the liquid to anundesirable height in the pump when the inlet of the displacementchamber is opened, a bypass around the sealing partition which is openedwhen the valve means is reciprocated to close the inlet of thedisplacement chamber, whereby liquid confined below the sealingpartition during filling of the displacement chamber will be dischargedthrough such bypass into the upper part of the eduction pipe and will beexpelled to the surface under normal, available gas pressure in asuccession of slugs which do not exceed a determinable maximum weight,regardless of high liquid level in the well or high formation pressure;all as more fully hereinafter set forth and as claimed.

My prior Patent No. 1,890,720, discloses pneumatic pumping apparatus ofwhich the present invention is an improvement. The general type of pumpthere disclosed is particularly adapted for oil well operation in whichthe oil is raised in stages and discharged in the form of slugs underpressure of gas forced into the well tubing. The oil is admitted atintervals to a displacement chamber through a valved inlet and when the`chamber is filled with liquid, the valve is closed and gas is admittedto discharge it to the surface through a ball check valve in theeduction pipe. 10 Thus, in operation, the displacement chamber isalternately filled and emptied, and the oil is discharged from the wellin a series of slugs.

As long as the pressure above the check valve in the eduction pipe canbe maintained at a 45 higher value than the submergence pressure whichacts to open the valve the displacement chamber and tube string will notbe lled to a height requiring greater ithan normal working pressure toexpel the liquid. With high sub- 50 mergence head, however, a muchgreaterpressure is required to start pumping after a shutdown than isnecessary to continue the operation, and in some instances the availablepressure is insumcient, with the result that pumping can- 55 not beresumed.

In oil well operations production may be small but formation pressurehigh enough to build up a 'high liquid level when the pump is shut down.Such a condition exists in the East Texas field where under prorationrequirements the allow- 5 able production is small and it is accordinglypreferable in operating to submerge the pump in several hundred feet ofoil in order to obviate frequent resetting as the level drops. Moreover,it is necessaryto produce at a low rate, and if 10 continuous operationis maintained the tubing must be allowed to remain in thedown positionfor several minutes during each cycle to prevent waste of gas which, inthe up position, is vented from the displacement chamber. In the down 15position of the tubing, however, the displacement chamber is relieved ofpressure, and the tubing may consequently fill practically to theIliquid level of the well. If the time is shorter, somewhat less oil istaken into the pump and a shorter 20 slug is consequently delivered, butwhere slugs of varying length and therefore of varying weight aredischarged, the pressure requirements fluctuate and the resultingoperation is less economical. 25

It is desirable that the slug length be substantially uniform so thatthe gas pressure required for pumping may be determined and fairlyconstant.

My present invention attains its object of re- 30 liable and economicaloperation by insuring that the liquid slugs which are ejected by thepump Will not be of greater weight than can be handled by the availablegas pressure at the Well.

Another object which is accomplished is to 35 provide an eduction pipedivided by a sealing partition into sections which are out ofcommunication with each other when liquid enters the pump from the well,but `which communicate through a bypass around the partition when theliquid 40 inlet is cut off, thereby to permit discharge of the liquidconfined below the partition through such bypass to the surface of thewell under available pressure.

A further` object is to provide a deep well pump in which the liquidfrom the well will not rise above a predetermined and desirable levelnotwithstanding conditions of submergence head or intermittentoperation.

A still further object is to provide a deep well pump in which adeterminable, maximum quantity of liquid is admitted in each cycle ofoperation and is then discharged by gas pressure, the liquid beingthereby raised to the surface in a succession of slugs of substantiallyuniform weight.

Other and further objects will be apparent from the followingdescription andY drawing wherein Figs. 1, 1-a and l-b are verticalsectional views of the upper, intermediate and lower portions of thepump valve assembly and-are to be considered as constituting acontinuous structure:

Fig. 2 is a horizontal sectional view along the line 2-2 of Fig. l-a.

Fig. 3 is a vertical sectional view of the intermediate portion of amodiiied form of pump valve, in the region corresponding to that shownin Fig. l-a.

Referring more particularly to the drawing, the pumpvalve assemblycomprises inner and outer concentric strings of tubing consisting ofaxially aligned and connected pipev sections. Only the lower part of thepump assembly is shown in the drawing wherein, for clarity ofillustration, the consecutive portions of the pump are shown separately.

The outer string of tubing I0 includes ,the aligned pipe sections II andI2 which are connected by a threaded nipple I3. (Figs. 1 and l-a.) Atits lower end, the pipe section I2 threadedly receives anY extension I4which, as shown in Fig. 1b, constitutes an enlarged displacement chamberinto which uid is admitted from the well upon reciprocation of the innertube string to be described.

The nipple I3 has opposite tubular extensions I5 and I5 which extendinto the pipe sections and I2 respectively and are supported at theirends within the outer tube string by lugs |1 and I8. The -nipple I3 andits extensions together constitute a valve cylinder in which a.reciprocating piston-type valve |9 is slidably received.

The piston valve I9 is attached to the inner tube string 20 at its upperend and at its opposite end has a tubular extension 2| (Fig. 1-b)terminating in a head 22 which slides in sleeve 23 of reduced diameterextending downwardly from the displacement chamber I4. The sleeve 23 hasports 24 for admission of well uid to the' displacement chamber when thepiston valve is in. In the upper position of thev lower position. valve.as shown in Fig. 1--b, the head 22 seals the inlet of the displacementchamber.

Ports 25 extend through the wall of the piston valve extension 2| andprovide communication between the displacement chamber and the interiorof the piston valve which constitutes an eduction passageway from thedisplacement chamber.

The body of the piston valve may conveniently have portions of reduceddiameter to define spaces between it and valve cylinder. The portions ofpiston not so reduced constitute heads which may be packed to preventleakage of liquid from the spaces so defined. A sealing partition 26divides the piston valve into upper and The upper portion of the pistonvalve as shown in Fig. 1 may be formed with ports 35 through which gasunder pressure may be injected from the surface of the well when thehead 31 is moved downwardly from the position shown, whereupon gas williiow through ports 38 and the annular space 38 around the valve into theeduction passageway through the ports 35 to assist in raising the liquidto the surface. y

In the pomtion of the valve shown in Fig. 1 the ports 38 are opened forthe flow of gas under pressure from the surface of the well to the space39 around one of the reduced portions of the piston valve. As shown inFig. 1a, the ports 48 are also open to admit gas to the space 4| andaround the radially spaced arms 42 into the displacementchamber.

The radial arms .42 (Figs. l-a and 2) have l ports'43 which extend tothe outside of pipe I2 for a purpose to be presently described.

Assuming that the pump displacement chamber is filled with liquid andthe valve is in the position shown in the drawing, gas under pressure isforced from the surface of the well between the inner and outer tubestrings, downwardly through ports 35, space 39 and ports 48 into thespace 4| which communicates with the interior of the displacementchamber. The downward pressure of gas on the liquid contained in thechamber will force it through the ports 25 upwardly into the valveextension 2|. The liquid cannot flow past partition 25 in the pumpvalve, so consequently its path of ilow is through ports 28, space 30and ports 32 into the annular space 33 from which it passes throughports 3| and the space 29 around the valve to the upper ports 21 andback into the eduction passageway above the partition 25. From here itmay rise freely to the surface of the well or, as described below, maybe given additional impetus on the succeeding down stroke .of theplunger'by gas mjecte through the ports 36-35 from the source ofpressure at the surface of the well.

The displacement chamber now being emptied the pump valve assembly isreciprocated to the down position. In the down position, the piston head31 comes to rest below ports 36 and cuts off the flow of gas to thedisplacement chamber via space 39. In the embodiment shown, when thehead 31 has come to rest in the down position, space 38 is brought intoregistry with ports 36 to permit gas from the source of pressure to passfromy ports 38 through space 38 and ports 35, where it enters theeduction passageway above the sealing partition 26 and expels any oilabove this point by air lift. 'I'he same movement of the valve vents thedisplacement chamber by' relieving it of gas pressure, the gas flowingtherefrom through space 4|, ports 40 (Fig. l-a) and space 39 around the'valve to the radial exhaust ports 43. y

'I'he pressure within the displacement chamber being thus relieved, thefoot valve shown in Fig. 1b is nowin the lower position, and inlet ports24 are uncovered to admit liquid from the well which flows up into thedisplacement chamber and into the pipe 2|. If the well has high liquidlevel the pump will ordinarily tend to ll to that high level, but inaccordance with my invention its rise is limited by the partition 26. Inthis intake position of the valve the ports 32 are closed, and theliquid rising through the eduction passage and passing out through ports28 will not be bypassed around the partition. Thus, notconfined belowthe partition 26 is calculated to be expelled by normal available gaspressure, whereas without this arrangement and construction of pumpelements, it could rise to a higher level, in which case its weightmight be sumcient to prevent pumping by the pressure available at thewell. The liquid which is received within the displacement chamber andthat portion at the piping below the partition '26 is of determinablemaximum lmass `and weight, and as it is transferred from the lowersection to the upper section ofthe eductlon passage in the valve at eachcycle of reciprocation it is discharged to the surface of the well in asuccessionof liquid slugs of uniform length, or under varyingconditions, of definite maximum weight.

A modied form of the invention is shown in Fig. 3 wherein an outer tube50 mounts a valve cylinder 5I spacedl from its interior wall. The valvecylinder 5I receives a tubular reciprocating valve 52 which has ports 5Iand 54 on opposite sides of the partition or seal 55. Valve cylinder 5ihas a portion of enlarged internal diameter dening an annular space 5Baround the piston which establishes communication between the ports 53and 54 when the valve is in the position shown and which cuts oficommunication between the two when the valve is in lowered pd-V sition.This modified form of valve carries a foot valve such as is illustratedin Fig. 1b of the drawing.

In both the preferred and modified pump structures herein described, theports 35 (Fig. l) throughwhich gas is admitted under pressure to assistin raising the liquid to the surface after it has been transferred tothe upper section of the eductlon pipe above the partition may beomitted without departure from the invention.

lErom.l the foregoing it will be apparent that my invention provides apneumatically operated deep well pump with means for limiting thecapacity of its intake and consequently permitting operation undernormal, available pressure whereby the liquid is discharged in slugs ofdeterminable and desirable weight.

What I claim is:-

l. A deep well pump comprising a tube string, a displacementchambercarried thereby to extend into the liquid in a well, a source ofpneumatic pressure, a reciprocable eductlon pipe,

valve means actuated by reciprocation of the` eductlon pipe foralternately admitting liquid from the well to the displacement chamberwhile venting the same, and expelling such -liquid therefrom underpneumatic pressure from said source, a, sealing partition in saideductlon pipe to limit theamount oi liquid admitted in the successivereciprocations of such pipe, a by-pass around said partition and valvemeans actuated by reciprocation of said eduction pipe to close theby-pass while liquid from the well is 'being admitted to saiddisplacement chamber` and to dividing said yeductlon pipe into upper andlower` sections, a displacement chamber carried by the tube string incommunication with the eductlon pipe below said partition, an inletvalve under control of the eductlon pipe for admitting liquid to thedisplacement chamber, valve means associated with said eductlon pipe foradmitting gas under pressure to the displacement chamber when the inletvalve is closed, and alternately to that section of the eductlon pipeabove said partition, further valve means associated with said eductlonpipe for bypassing said partition intermittently as the eductlon pipe isreciprocated and the inlet valve closed, thereby to permit liquid to beexpelled from the displacement chamber and around said partition intothe section of eductlon pipe thereabove wherein upon continuedreciprocation of the eductlon pipe gas is injected to assist indischarging the liquid so transferred .and will deliver it to thesurface as a slug of determinable, maximum Weight.

3. A deep well pump comprising a tube string,

a displacement chamber carried by said tube .string and adapted toextend into the liquid in a ternately admitting gas under pressure tosaid displacement chamber and expelling the retained liquid therefromthen stopping the passage of gas to said displacement chamber whileAadmitting gas under pressure to the upper portion of the eductlon pipe,a sealing partition in the eductlon pipe to limit the rise of liquidtherein when the inlet valve is opened, means for bypassing saidpartition upon reciprocation of said eduction pipe to close the inletvalve and admitting gas under pressure to said displacement chamber,thereby to force the conned liquid from the displacement chamber throughsuch bypass and into said eduction pipe above said partition, and portsopened by reciprocation of said eduction pipe at the same time the inletvalve is opened for venting the displacement chamber and relieving it oipressure whereby it is relled with liquid from the well d. Pumpingapparatus comprising a displacement chamber adapted to extend into theliquid oi' a Well, a valve for admitting liquid from the Wellthereinto', a reciprocable eductlon pipe in communication with saiddisplacement chamber and arranged to open and close said valve in itsreciprocation, a source of pneumatic pressure, valve means carried bysaid eduction pipe for establishing communication between the source ofpneumatic pressure and said displacement chamber, a seal dividing saideduction pipe into upper and lower sections, ports above and below saidseal adapted to be opened and thereby to permit the bypass flow ofliquid from the lower to the upper section of the eduction pipe when itis reciprocated to close the valve admitting liquid to the displacementchamber, and closed to prevent flow of liquid from the lower section ofthe eduction pipe to the upper when such valve is' open, whereby apredetermined maximum quantity of liquid is initially' confined belowsaid partition in the eduction pipe .and subsequently is expelled to thesurface of the well under the inuence of pneumatic pressure applied fromthe source in the reciprocation of the eduction pipe. .5.' A deep wellpump comprising a displacement chamber adapted to extend into the liquidin a welll means for admitting gas under pressure to said displacementchamber during periods when said displacement chamber is not incommunication with the liquid in the Well, an eduction pipecommunicating with said dis-l placement chamber, means for reciprocatingsaid eduction pipe, a valve actuated by the eduction pipe in`itsreciprocation for controlling the inlet of liquid from the well to saiddisplacement chamber, a seal dividing the eduction pipe into upper andlower sections, ports in said eduction pipe above and below said seal,means adapted to place said ports in communication and valve meanscarried by said eduction pipe cooperat- 'ing with said communicationmeans to establish a bypass around said seal when the eduction pipe isreciprocated to actuate said inlet valve and cut-off communication withthe well, thereby to permit the discharge of liquid from saiddisplacement chamber under pressure of gas admitted thereto, said valvemeans serving to close off communication between the upper and lowersections of the eduction pipe when communication between the well andthe displacement chamber is reestablished by opening of the inlet valve,whereby only suicient liquid is admitted to the pump as may be expelledin a slug of predetermined maximum weight.

6. A pump for delivering successive and substantially uniform slugs ofliquid to the surface of a well comprising a displacement chamberadapted to extend into the liquid of a well, a reciprocable eductionpipe extending into said displacement chamber, a sealing partition insaid eduction pipe dividing it into upper and lower sections, a sourceof iiuid pressure, inlet valve means carried by said eduction pipe foradmitting fluid under pressure periodically to said displacementchamber, ports in said eduction pipe above and below the said partitionmeans cooperating with said ports to form a passageway adapted toby-pass liquid from said displacement chamber around said partition tothe upper section of the eduction pipe while pressure is applied to theliquid therein from said source, means acting to close said passage-wayupon further reciprocation of the eductionpipe to prevent passage ofliquid around said partition during periods when iluid under pressure isnot admitted to said displacement chamber and valve means actuated byreciprocation of the eduction pipe to admit liquid from the well intothe displacement chamber during periods when the iiuid pressure is cutoff therefrom and to cut ofi the displacement chamber from communicationwith the well liquid during periods when iluid pressure from said sourceis admitted to said displacement chamber vwhereby said displacementchamber will be alternately filled and emptied but the amount of liquidentering the pump from the well will be limited by said partition sothat successive slugs of convenient weight will be formed to bedischarged tnrough the eduction pipe around said partition to thezirface of the well when the pump is in opera- 7. A deep well pumpcomprising a tube string, a displacement chamber at the end of the tubestring adapted to extend into the liquid in a well, a reciprocableeduction pipe carrying a foot valve at its endto establish communicationperiodically between the displacement chamber and the well, saideduction pipe above its lower end constituting a hollow, piston-typevalve in communication with the displacement chamber, a seal dividingsaid piston-type valve into upper and lower sections, ports above andbelow said seal, means in the wall of said tube string adapted toregister with said ports and place them in communication when placed inregistry by movement of the eduction pipe and foot valve in a directionto cut oi communication with the well and adapted to close said portsfrom communication when the eduction pipe is in position to open thefoot valve, whereby when communication with the well is establishedliquid cannot rise in the tubing above the level of such seal, andmeansadapted to admit gas under pressure to the displacement chamberwhen cut off from communication with the well, whereby liquid in thetubing subsequently will be discharged to the surface of the well as aslug of definite, maximum weight.

8. A pump for delivering successive and substantially uniform slugs ofliquid to the surface of a well by pneumatic pressure comprising a tubestring, a displacement chamber carried by said tube string and adaptedto extend into the liquid of the well, a valved inlet in saiddisplacement chamber for intermittently admitting well liquid thereto,an eduction pipe reciprocable within said tube string and communicatingwith said chamber at its lower end, a seal within said eduction pipedividing., it into upper and lower compartments, a source of pneumaticpressure, valve means actuated by said eduction pipe for alternatelyconnecting iirst the displacement chamber and then the upper compartmentof said eduction pipe with the source of pneumatic pressure, a by-passconnecting the upper and lower compartments of the eduction pipe aroundsaid seal and means actuated by reciprocation of the eduction pipe toclose said by-pass when the source of pneumatic pressure is connected tothe upper part oi the eduction pipe, whereby rise of the well liquidabove said seal is prevented when said displacement chamber is cut oifrom communication with said source of pneumatic pressure but passage ofthe well fluid around the seal is permitted when said displacementchamber is connected with said source of pneumatic pressure to dischargethe contents of the chamber into the upper compartment of the eductionpipe.

ROY L. CHENAULT.

